Kerf-cutting machine



July l1, 1939. T. E. PRAY I 155,575

KERF-CUTTING MACHINE.

Filed sept. 15, 1957 4 sheets-sheet 1 CFM?.

July 11 1939- T. E. PRAY 2,165,675

A KERF-CUTTING MACHINE Filed Sept. 13, 1957 4 Sheets-Sheet 2 niiiil..

Illl

T. E. PRAY July 11, 1939.

KERF- CUTTING MACHINE Filed Sept. 13, 1937 4 Sheets-Sheet 3 4 Sheets-Sheet 4 l -'TfI-n T. E. PRAY KEEP-CUTTING MACHINE Filed sept. 13, 1937 July 1l, 1939.

Patented July 11,1939

2,165,67 KERF- CUTTING MACHINE Thomas E. Pray, Chicago, Ill., assignor to Goodman Manufacturing Company, Chicago, Ill., a corporation of Illinois Application September 13, `1937, Serial No. 163,565

14 Claims.

seam to fall to the ground without blasting or' shooting.

Another object of my invention is to provide a simpliiied, inexpensive, and efficient construction of mining machine so arranged that the cutter bars may be positioned to cut a pair of parallel spaced kerfs one of which is adjacent the mine roof, and by a simple adjustment may cut another pair of kerfs on each side of the lowermost of said first-mentioned kerfs, one of which last-mentioned kerfs is adjacent the mine bottom.

Still another object of my invention is to provide a novel means for supporting the machine to permit it to slide and cut while sliding along thc mine bottom, which supporting means is adjustable to position one of the bars adjacent the roof and positionL the same bar adjacent the ground when it has been rotated through 180 about an axis extending longitudinally of the machine and which is also so arranged as to permit the height of the machine to be reduced to a minimum for transportation about the mine.

Other objects of my invention will appear from time to time as the accompanying specification proceeds.

My invention may be more clearly understood with reference to the accompanying drawings wherein:

Figure 1 is a diagrammatic plan View of a machine constructed in accordance with my invention, in position in a working place of a mine during the cutting operation;

Figure 2 is a side elevation of the machine shown in Figure 1 with one of the cutter bars positioned to cut along the roof;

Figure 3 is a side elevation of the machine shown in Figure 1 showing one of the cutter bars positioned to cut along the mine bottom;

Figure 4 is an enlarged side elevation of the machine shown in Figure 1;

Figure 5 is a rear end view of the machine shown in Figure 1 drawn to an enlarged scale;

Figure 6 is a fragmentary side elevation of the (C1. 26a-2s) rearward portion of the machine shown in Figure 1 anddrawn to the same scale as Figure 5, with certain parts broken away and shown'in section;

Figure 7 is an enlarged fragmentary plan view of the forward portion of the machine with certain parts broken away and shown in section;

Figure 8 is an enlarged fragmentary longitudinal sectional View of the forward portion of the machine shown in Figure l;

Figure 9 is a sectional View taken substantially along lines 9 9 of Figure 7; and

Figure 10 is an enlarged transverse sectional view of the cutter head taken substantially along lines Ill- I0 of Figure 4.

With reference now in particular to the drawings, the mining machine, as herein shown, operates on principles somewhat similar to the ordinary kerf-cutting machine of the room and pillar type, that is; it is provided with a pair of Winding drums I0, I0 on opposite sides of the rearward end thereof, each of which has a flexible cable II wound thereon, the flexible cable on the advance side of the machine acting as a feeding means for moving the machine across the working face during cutting, and the cable on the retreating side of the machine acting as a retarding means to hold the machine up to the face and the cutter bar in the desired relationship with respect to the coal face.

The machine, as herein shown, is provided with a motor I2 and a feeding section I3 disposed rearwardly of said motor, which includes the winding drums I Il, I0 driven from said motor in a manner well-known to those skilled in the art, and not shown or described herein since it is no portionof my present invention. A cutting section I4 is disposed forwardly of said motor and includes a frame I5 secured to said motor and projecting forwardly therefrom. A cutter head I6- is mounted on said frame for pivotal movement with respect thereto about an axis eX- tending longitudinally of the machine, and has a pair of' spaced-cutter bars I'I and I 3 projecting therefrom inv parallel spaced relationship with respect to each other, which have cutter chains I9 and 20, respectively, movable thereabout ink closed orbital paths. Said cutter chains are meshed with sprockets 2I and 22 respectively which are mounted on opposite ends of a shaft 23 which is journaled in said cutter head and driven from the motor I2 in a manner which will moreV clearly appear as thisy specication proceeds.

Referring now in particular to the cutting section I4 and several of the novel features of my invention, a rearwardly projecting annular portion of the cutter head IS is mounted in an annular recess 24 for pivotal movement with respect thereto about a longitudinal axis. Said recess is formed in the forward end of the frame l5 and the projecting portion of said cutter head is retained therein by an annular ring 25 secured to the forward end of the frame I5 in a suitable manner. Said ring abuts a shouldered forward face of said rearwardly projecting annular portion of said cutter head and retains said annular portion on said frame so the entire cutter head may be rotatably moved with respect to said frame.

The cutter head I6 is turned about its axis of pivotal connection to the machine by means of pinions 2G, 2G on shafts 21, 21 which are mounted in and project rearwardly from said cutter head. Said pinions mesh with an internal gear 28 keyed to the forward portion of the` frame |5 adjacent the annular recess 24. Said pinions are also adapted to be selectively meshed withk a spur gear 2S, herein shown as being formed integral with a sleeve 3|! which is feathered on a sleeve 3|. Said last-mentioned sleeve is journaled in the frame I5 coaxial with the turning Aaxis of the cutter head. Thus when said pinions are driven by power, they will walk around said internal gear and cause pivotal movement of said cutter head about an axis extending longitudinally of the machine.

The drive from the motor I2 to the sleeve 3| and spur gear 29 includes a motor shaft 32 which, as herein shown, is coaxial with the sleeve 3|. A bevel gear 33 is journaled in the frame I5 for rotation about an axis parallel to the shaft 32. Said bevel gear is driven from said shaft by means of a suitable chain and sprocket drive generally indicated by reference `character 34. A pair of cppositely disposed bevel gears 36, 36 are meshed with and driven from said bevel gear, and said bevel gears form a selective reversible drive for a transversely extending shaft31 which is journaled in the frame I5 and on which said bevel gears are freely mounted. Suitable clutch means including a clutch collar 38 are provided to drive said transverse shaft from either of said bevel gears in an ordinary manner and thus reverse the direction of rotation of said-shaft without reversing the direction of rotation of said motor. A worm 39 is keyed on said last-mentioned shaft which meshes with and drives a worm gear 40 keyed on the sleeve 3|.

The sleeve 30 is provided with a peripheral groove 43 adapted to be engaged by a shipper yoke 44 for shifting said sleeve along the sleeve 3| and engaging the spur gear 29 with the pinions 26, 26 to turn the cutter head I5 by power.

Suitable means are provided to lock the cutter head it from pivotal movementand hold the cutter bars in various desired fixed cutting positions, which, as herein shown, include a pin 45 mounted in a lateral extension 46 from the cutter head I 5. Said pin has teeth formed on its end which are adapted to engage suitable teeth 41, 41 formed in the forward face of the annular ring 25 and projecting forwardly therefrom. Said pin is operated by means of a suitable hand lever 4B and link 49 by means of an eccentric 50 on said lever which engages said link.

The shaft 23 and cutter chain drive sprockets 2| and `22 are selectively driven from the motor by means of a shaft 5I extending through the sleeveY 3| and journaled for rotation about an axis coaxial with the axis of rotation of said sleeve. Said shaft is driven from the forward end of the motor shaft 32 by means of a iiexible coupling generally indicated by reference character 53. A bevel pinion 54 is mounted on the forward end of the shaft 5| and meshes with a bevel gear 55 freely mounted on the shaft 23. Said bevel gear is selectively connected with said shaft, for driving said shaft, by means of a jaw clutch generally indicated by reference character 56 (see Figure B).

The cutter bars |1 and I8 are slidably mounted in grooves 51, 51 formed in cutter bar support members 58, 58 projecting from opposite sides of the forward end of the cutter head I6. Tension of the respective cutter chains I9 and 20 is adjusted by means of suitable adjusting mechanisms engaging each of said cutter bars, the construction of each of which is substantially the same so one only need herein be described. Said adjusting mechanism includes a lever arm 59 pivoted to the cutter bar support member 58 intermediate its ends. One end of said lever arm engages the rear end of the cutter bar in a slot 50 formed in the central portion thereof. The other end of said lever arm is pivoted between the furcations 6| of a bifurcated end of a threaded member 52. Said threaded member extends through a suitable opening in a forward spacing wall 63 extending between the support members 58, 58. A nut 64 is threaded on said threaded member and has a portion which extends through the wall 63. A collar B5 abuts the opposite side of said wall from the lever arm 59 and prevents translational movement of said nut with respect to said wall so that turning of said nut in one direction will slide the cutter bar in a forward direction to tighten the chain, and turning of said nut in an opposite direction will permit loosening ofthe chain in an obvious manner.

It may be seen from the foregoing that the cutter bars I1 and I8 are mounted on the frame |5 for pivotal movement with respect rthereto about a longitudinal axis and that said cutter bars are oif center from said axis so that the cutter bar I1 may be an upper cutter bar when said cutter head is in one position, and may be a lower cutter bar when said cutter head is rotated to an opposite position, and so that the cutter bar I8 may cut between the kerfs cut by the cutter bar |1 and on opposite sides of the turning axis of said cutter head.

Referring now in particular to the novel arrangement for supporting the machine for slidable movement along the mine bottom so that the cutter bar |1 may be positioned to cut along the roof or floor of the mine, which is also so arranged that the height of the machine may be reduced for transportation from workingvplace to working place, the rear end of the machine is supported on a shoe 61. Said shoe projects downwardlyk from the feeding section I3 and extends transversely across the rear under side thereof. The under side of said shoe is of an arcuate formation and forms an arcuate ground engaging face formed about an axis which extends transversely of the machine, which face forms a fulcrum about which the machine may pivot.

The forward end of the machine is adjustably supported on a transversely extending supporting shoe 69. Said sh'oe has a pair of threaded shafts 16, 10 transversely pivoted to opposite sides thereof, which shafts, as herein shown, are threaded in hubs 1|, 1| of bevel gears 12, 12.

Said bevel gears are journaled on their hubs in lateral extensions 13, 'I3 from the forward portion of the frame I5, and are held from vertical displacement with respect to said frame 'by means of cylindrical thrust members 14, 14,

15, 'I6 on opposite ends of a transversely extending shaft TI. Said shaft is suitably journaled in said frame and is selectivelyl driven from the sleeve 3l by means of a pair of meshing helical gears 18, i8 and a suitable clutch generally indicated by reference character 1S. ySaid clutch is herein shown as being of the friction conical type and includes a conical friction engaging drum Sii feathered on the transverse shaft TI and slidably moved therealong in a suitable manner for engagement with an inner frusto-conical surface 8l projecting from the helical gear coaxial with said shaft.

Thus the entire machine may be pivoted about the shoe Si by power to adjust' the angle of the cutter bars' I'IA and I8 with respect to the ground, and position the cutter bar I'I adjacent themine roof in seams of varying thicknesses for cutting a kerf along the roof when the cutter head I6 is in one position and along the ground to cut a kerf along the ground when said cutter head is rotated 180 to an opposite position.

Referring now to the use and operation of the machine described herein, when the ymachine is positioned in the working place to feed or sump the cutter bars into the coal seam, the cutter bar Il is rst adjusted so that its outer end is adjacent the roof by rotatably adjusting the cutter head I6' to the proper position and locking said cutter head in such a position and then elevating the forward end of the machine about the shoe 6l by means of the extensible supporting connection between the forward end of the machine and the shoe 59, in the hereinbefore described manner. The cutter bars II and Iii are then sumped intothe coal and fed across the coal iace by means of the flexible cables II, II in a manner similar to that used in sumping and feeding the common form of mining machine of the room and pillar type. After said cutter bars have each simultaneously cut a kerf across the coal face, one of which kerfs is adjacent the roof and the other of which is intermediate the roof and bottom and beneath the turning axis of the cutter head, the machine is withdrawn from the face and moved back to the right hand side of the working place (providing the machine is working from right to left) When the machine is so positioned the cutter head I6 is rotated 180 to position the cutter bar I'I in a lowermost position with respect to the machine frame so it may be adjusted to cut along the ground and the cutter bar I8 may be positioned above the turning axis of the cutter head and above the kerf rst cut by it. The machine is thenangularly adjusted with respect to the mine bottom by means of the adjustable shoe 69 so that the outer end of the cutter bar I'I is adjacent the mine bottom and the two cutter bars are then sumped into the coal and fed across the face in the usual manner. While these second two kerfs are being cut, the cutter chains moving about their respective cutter bars will-cutkerfs-on each side'of the lowermostkerf cut: in the -rst cutting operation which'ewill break down the coal intermediate the top and bottom kerfs. Thus, the entire coal seam may be mined in a simple and efficient manner eliminating the use of powder for breaking down the coal. f

While I have herein shown and described one form in which my invention may be embodied, it will be understood that the construction thereof and the arrangement of the Various parts may be altered without departing from the spirit and scope thereof. Furthermore, I do not wish to be construed as limiting myself to the specific embodiment illustrated, excepting as it may be limited in the appended claims.

I claim as my invention:

1. In a mining machine, a frame, a cutter head mounted thereon for rotational movement with respect thereto about an axis extending longitudinally of said frame, said cutter' head having cutter bars projecting from opposite sides thereof,

each of said cutter bars having a cutter chain movable thereabout, and means for `adjustably supporting said frame to position said cutter bars to cut a plurality of spaced apart kerfs, one of which is along the mine roof when said cutter 1 head is in one position and to out a plurality of spaced apart kerfs on opposite sides of the lowermost of said first-mentioned kerfs, one of which is along the mine bottom when said cutter head is rotatably moved to an opposite position ini cluding a shoe having slidable engagement with the ground and having adjustable supporting engagement with the forward end of said frame whereby the forward end of said frame may be vertically adjusted with respect thereto.

2. In a mining machine, a frame, a cutter head mounted thereon for rotational movement with respect thereto about an axis extending longitudinally of said frame, said cutter head having cutter bars projecting from opposite sides thereof, said cutter, bars having cutter chains movable thereabout, and means for adjustably supporting said frame to position said cutter bars to cut a plurality of spaced apart kerfs, one of which is along the mine roof when said cutter head is in one position and to cut a plurality of spaced apart kerfs on opposite sides of the lowermost of said first-mentioned kerfs, one of which is along the mine bottom when said cutter head is rotatably moved to an opposite position including a shoe having slidable engagement with the ground and having adjustable supporting engagement with the forward end of said frame whereby the forward end of said frame may be vertically adjusted with respect thereto, and another shoe adapted to support the rearward end of said frame on the ground, said shoe having an arcuate surface engaging the ground, the axis of Which extends transversely of the machine whereby said shoe may form a fulcrurn about which said frame may pivot.

3. In a mining machine, a frame, a cutter head mounted thereon for rotational movement With respect thereto about an axis extending longitudinally of said frame, said cutter head having a cutter bar projecting from each side thereof, said cutter bars each having a cutter chain movable thereabout, and means for adjustably supporting said frame to position said cutter bars to cut a plurality of spaced apart kerfs, one of which is along the mine roof when said cutter head is in one position and `to cut a pluralitycf spaced apart kerfs on opposite sides of the lowermost of said first-mentioned kerfs, one of which is along the minefbottom when said cutter head is rotatably Vmoved to an opposite position including a shoe having slidable engagement with the ground, an extensible supporting connection between the forward end of said frame and said shoe for vertically adjusting the forward end of said frame withrespect to said shoe, and another shoe spaced rearwardly from said first-mentioned shoe and forming a fulcrum about which said frame may pivot.

4. In a mining machine, a frame, a cutter head mounted thereon for rotational movement with respect thereto about an axis extending longitudinally of said frame having a pair of spaced apart cutter bars projecting from opposite sides thereof having cutter chains movable thereabout, and means for adjustably supporting said frame to position said cutter bars to cut a pliuality of spaced apart kerfs, one of which is along the mine roof when said cutter head is in one position and to cut a plurality of spaced apart kerfs on opposite sides of the lowermost of said firstmentioned kerfs, one of which is along the mine bottom when said cutter head is rotatably moved to an opposite position including a shoe having slidable engagement with the ground, an extensible supporting connection between the forward end of said frame and said shoe for vertically adjusting the forward end of said frame with respect to said shoe, and another shoe spaced rearwardly of said first-mentioned shoe and forming a fulcrum about which said frame may pivot, said shoe having an arcuate surface engaging the ground, the axis of which extends transversely of the machine.

5. In a mining machine, a frame, a cutter head mounted thereon for rotational movement with respect thereto about an axis extending longitudinally of said frame and having a pair of spaced cutter bars projecting from opposite sides thereof having cutter chains movable thereabout, and means for adjustably supporting said frame to position said cutter bars to out a plurality of spaced apart kerfs, one of which is along the mine roof when said cutter head is in one position and to cut a plurality of spaced apart kerfs on opposite sides of the lowermost of said firstmentioned kerfs, one of which is along the mine bottom when said cutter head is rotatably moved to an opposite position including a shoe having slidable engagement with the ground, and adapted to support the forward end of said frame for vertical adjustment with respect to the ground, another shoe supporting the rearward end of said machine and forming a fulcrum about which said frame may pivot, and power means for vertically adjusting said frame with respect to said forward shoe including a threaded shaft on each side of said frame, said shafts being pivotally mounted on said shoe for movement about a common transverse axis and supporting said frame for translational movement with respect thereto.

6. In a mining machine, a frame, a cutter head mounted thereon for rotational movement with respect thereto about an axis extending longitudinally of said frame and having cutter bars projecting from opposite sides thereof, said cutter bars each having a cutter chain movable thereabout, and means for adjustably supporting said frame to position said cutter bars to cut a plurality of spaced apart kerfs, one of which is along the mine roof when said cutter head is in one position and to cut a plurality of spaced apart kerfs on opposite sides of the lowermost of said first-mentioned kerfs, one of which is along the mine bottom when said cutter head is rotatably moved to an opposite position including a shoe having slidable engagement with the ground, and adapted to support the forward end of said frame for vertical adjustment with respect to the ground, another shoe supporting the rearward end of said machine and forming a fulcrum about which said frame may pivot, and power means for vertically adjusting said frame with respect to said forward shoe including a threaded shaft on each side of said frame, said shafts being pivotally mounted on said shoe for movement about a common transverse axis and supporting said frame for translational movement with respect thereto, a power driven shaft extending transversely of said frame, a gear having threaded engagement with each of said threaded shafts and a drive connection between opposite ends of said transverse shaft and said gears.

'7. In a mining machine of the class described,

a motor, feeding mechanism disposed rearwardly of said motor including a flexible feeding member, cutting mechanism disposed forwardly of said motor including a cutter head mounted for rotational movement about an axis extending longitudinally of the machine, said cutter head having a pair of spaced apart cutter bars projecting from opposite sides thereof having cutter chains movable thereabout, means driven .from the forward end of said motor for turning said cutter head, means driven from the forward end of said motor for driving said cutter chains about said cutter bars, and other means driven from the forward end of said motor for angularly adjusting the position of said cutter bars with respect to the ground so said cutter bars may cut a plurality of spaced apart kerfs, one of which is along the mine roof, when said cutter head is in one position, and to cut a plurality of spaced apart kerfs on opposite sides of the lowermost of said first-mentioned kerfs, one of which is adjacent the mine floor when said cutter head is in an opposite position.

8. In a mining machine of the class described, a motor, feeding mechanism disposed rearwardly of said motor and driven therefrom and including a winding drum having a flexible feeding member wound thereon, cutting mechanism disposed forwardly of said motor including a cutter head mounted for rotational movement about an axis extending longitudinally of the machine, said cutter head having a pair of spaced apart cutter bars projecting from opposite sides thereof having cutter chains movable thereabout, means driven from the forward endl of said motor for turning said cutter head, means driven from the forward end of said motor for driving said cutter chains about said cutter bars, and other means driven from the forward end of said motor for angularly adjusting the position'of said cutter bars with respect to the ground so said cutter bars may cut a plurality of spaced apart kerfs, one of which is along the mine roof, when said cutter head is in one position, and to cut a plurality of spaced apart kerfs on opposite sides of the lowermost of said first-mentioned kerfs, one of which is adjacent the mine floor when said cutter head is in an opposite position including a shoe slidable along the ground and an extensible drive connection between said motor and shoe.

9. In a mining machine of the class described, a motor, feeding mechanism disposed rearwardly of said motor and driven therefrom and including a winding drum having a flexible feeding member wound thereon, cutting mechanism disposed forwardly of said motor including a cutter head mounted for rotational movement about an axis y forward end of said motor for driving said cutter chains about said cutter bars, and other means driven from the forward end of said motor for angularly adjusting the position of said cutter bars with respect to the ground so said cutterbars may cut a plurality of spaced apartkerfs, one of which is along the mineA roof, when said cutter head is in one position, and to out a plurality of spaced apart kerfs on opposite sides of the lowermost of said first-mentioned kerfs, one of which is f adjacent the mine floor when said cutter head is in an opposite position including a shoe slidable along the ground and adapted to supporttheforward end of said machine for vertical adjustment with respect thereto, another shoe spaced rearwardly from said first-mentioned shoe and forming a fulcrum about which said frame may pivot, and an extensible drive connection between said motor and first-mentioned shoe. Y

10. In a mining machine of the class described, a motor, feeding 'mechanism disposed rearwardly of said motor and driven therefrom and including a winding drum having a flexible feeding member wound thereon, cutting mechanism disposed forwardly of said motor including a `cutter head mounted for rotational movement about an axis extending longitudinally of thev machine, said cutter head having a pair of spaced apart cutter bars projecting from opposite sides thereof having cutter chains movable thereabout, means driven from the forward end of said motor for turning said cutter head, means driven from the forward end of said motor for driving said cutter chains about said cutter bars, and other means driven from the forward end of said motor for angularly adjusting the position of said cutter bars with respect to the ground so said cutter bars may cut a plurality of spaced apart kerfs, one of which is along the mine roof, when said cutter head is in one position, and to out a plurality of spaced apart kerfs on opposite sides of the lowermost of said first-mentioned kerfs, one of which is adjacent the mine floor when said cutter head is in an opposite position including a shoe slidable along the ground and adapted to support the forward end of said machine for vertical adjustment with respect thereto, another shoe spaced rearwardly from said first-mentioned shoe and forming a fulcrum about which said frame may pivot, and an extensible drive connection between said motor and first-mentioned shoe including a shaft disposed forwardly of said motor and extending transversely thereof, a pair of gears driven from opposite ends of said shaft, a pair of threaded shafts pivotally mounted on opposite sides of said shoe, and a threaded drive connection between said gears and shafts for causing the forward end of said mining machine to movetranslationally with respect to said shafts upon rotation of said gears.

11. A mining machine adapted to cut while slidably moving along a mine bottom including a motor, feeding mechanism disposed rearwardly of said motor and driven thereby and including a winding drum having a flexible feeding member wound thereon, cutting mechanism disposed forwardly of said motor including a cutter head mounted for Yrotational movement about an axis extending longitudinally of the machine and having a pair of spaced apart cutter bars projecting from opposite sides thereof, said cutter bars having cutter vchains movable thereabout, means driven fromthe forward end of said motor for turning saidcutter head to position said cutter bars for cutting along, the vmine roof or floor, means driven from the forwardend of said motor for driving saidcutter chains about said cutter bars including a shaft journaled in said jcutter head 'and having sprockets on opposite ends thereof, and othermeans driven from the forward` endV of said motorfor angularly adjusting the',

position ofsaid cutteribarsv with vrespect to the ground sosaid cutterbarsmay cut a vplurality of spaced apart kerfs, one of which isalong the mine roof, when said cutter head is in one posi'- tion, and to cut a plurality of spacedfapart kerfs on Vopposite sides of the lowermost of said firstrnentioned kerfs, one of which kerfs is adjacent the mine floor when said cutter head is rotatably moved to an opposite position.

12. A mining machine adapted to cut while slidably moving along a mine bottom including a motor, feeding mechanism disposed rearwardly of and driven from `said motor including a winding drum having a flexible'feeding member wound thereon, cutting mechanism disposed forwardly of said motor including a cutter head mounted for rotational lmovement about an axis extending longitudinally ofthe machine and having a pair ofspaced apart cutter bars projecting from opposite sides' thereof, said cutter bars having cutter chains movable thereabout, means driven from the'forward end of said motor for turning said cutter head to-position said cutter bars for cutting along the mine roof or floor, means driven from the forward end of said motor for driving said cutter chains about said cutter bars including a shaft'journaled in said cutter head and having sprockets on opposite ends thereof meshing with said chains, and other means driven from the forward end of said motor for angularly adjusting the position of said cutter bars with respect to the ground so said cutter bars may cut a plurality of spaced apart kerfs, one of which is along the mine roof, when said cutter head is in one position, and to cut a plurality of spaced apart kerfs on opposite sides of the lowermost of said firstmentioned kerfs one of which kerfs is adjacent the mine oor when said cutter head is'rotatably moved to an opposite position including a shoe supporting the forward end of said mining ma-V chine for movement along the ground, and an extensible connection driven by said motor and interposed between the forward portion of said mining machine and shoe, for elevating the forward portion of said mining machine with respect to said shoe. e

413. YIn a mining machine adapted to cut while slidably moving along a mine bottom, a motor,

driven from said motor including a winding drum having a flexible feeding member wound thereon,

vsides thereof, said cutter bars having cutter chains movable thereabout, means driven from the forward end of said motor for rotatably adjusting said cutter head to position said cutter bars for cutting along the mine roof or floor, means driven feeding mechanism disposed rearwardly of and from the forward end of said motor for driving said cutter chains about said cutter bars including a shaft journaled in said cutter head and having sprockets on opposite ends thereof, and other means driven from the forward end of said motor for angularly adjusting the position of said Cutter bars with-respect to the ground so said cutter bars may cut a plurality of spaced apart kerfs, one of which is along the mine roof, when said cutter head is in one position, and to cut a plurality of spaced apart kerfs on opposite sides of the lowermost of said first-mentioned kerfs, one of which kerfs is adjacent the mine floor when said cutter head is rotatably moved to an opposite position including a shoe adapted to slidably engage the ground and support the forward end ofsaid mining machine for adjustment with respect thereto, another shoe spaced rearwardly of said first-mentioned shoe and forming a fulcrum about which said frame may pivot, and an extensible supporting connection between the forward end of said mining machine and rstmentioned shoe, the extension of which is controlled by said motor.

14. In a mining machine adapted to cut while slidably moving along a mine bottom, a motor, feeding mechanism disposed rearwardly of and driven by said motor and including a winding drum having a flexible feeding member wound thereon, cutting mechanism disposed forwardly of said motor including a cutter head mounted for rotational movement about an axis extending longitudinally of the machine and having a pair of spaced apart cutter bars projecting from opposite sides thereof, said cutter bars having cutter chains movable thereabout,` means driven from the forward end of said motor for turning said cutter head to position said cutter bars for cutting along the mine roof or oor, means driven from the forward end of said motor for driving said cutter chains about said cutter bars including a shaft journaled in said cutter head and having sprockets on opposite ends thereof meshing with saidcutter chains, and other means driven from the forward end of said motor for angularly ad? justing the position ofvsaid cutter bars With're# spect to the ground so said cutter bars maycut a plurality of spaced apart kerfs, one of which is along the mine roof, when said cutter head is in one position, and to cut a plurality of spaced apart kerfs on opposite sides of the lowermost of said first-mentioned kerfs when said cutter head is in an opposite position one of which kerfs is adjacent the mine floor, including a shoe adapted to slidably engage the ground and support the forward end of said mining machine for adjustment with respect thereto, another shoe spaced rearwardly of said first-mentioned shoe and forming a fulcrum about which said frame may pivot, and an extensible supporting connection between the forward end of said mining machine and first-mentioned shoe, the extension of which is controlled by said motor, said supporting connection including a shaft disposed forwardly of and extending transversely of said motor, a pair of gears driven from opposite ends of said shaft, a pair of threaded shafts pivotally mounted on opposite sides of said shoe, and a threaded drive connection between said gears and shaft for causing the forward end of said mining machine to move translationally with respect to said shafts upon rotation of said gears.

THOMAS E. PRAY. 

